Draft-regulating damper.



W. B. FOWLER.- DRAFT REGULATING 511111 1111.v APPLICATION FILED JUNE 3,1910.

984,550. 7 I Patented Feb. 21, 1911.

ZZZ7 065665r JFvUeziZEr 4% ym 3 m4 14,

1n: mmms Pun-Rs ca. WASHINGTON. n. ::v

WALTER B. FOWLER, OF LAWRENCE, MASSACHUSETTS.

DRAFT-REGULATING DAMPER.

Specification of Letters Patent.

Patented Feb. 21, -19.1.1.

Application filed June 3, 1910. Serial No. 564,785.

To all whom it may concern:

Be it known that I, l/Vaurnu IS. F owLnn, citizen of the United States,and resident of Lawrence, county of Essex, Massachusetts, have inventedcertain new and useful Improvements in Draft-Regulating Dampers, ofwhich the following is a specification.

This invention relates to draft-regulating dan'ipers and is intended toprovide a simple and efficient means for maintaining a properlyregulated control over such a damper to control, under varyingconditions, the admission of air into the smoke pipe, flue or chimney,to which the damper is applied.

One of the features characterizing the n'esent invention resides in theconstruction and arrangement of the supporting frame or casing and thedamper by which the instantaneous removal or insertion of the damperpermitted and also the tendency of the damper mechanism to become rustedin the frame is overcome.

Another important feature of the inven tion consists in the constructionand arrangement by which the adjustment of the 'n'essure-regulatingdevice controlling the action of the damper is effected to suit; varyingconditions.

These and other features of the invention will be more particularlyexplained in the specification following and. will be defined in theclaims forming part thereof.

In the drawings I have shown the preferred form of embodying myaforesaid im- PI'OVQI'HOIrtS, of which- Figure 1' is a front elevationof the complete device ready for application to service; Fig. 2 is aside elevation partly broken away; Fig. 3 is a vertical central sectionof the frame or casing; and Fig. 4 is a detail plan View of one of theregulating weights.

In the practice of my invention according to the form illustrated, Iemploy a supporting frame or easing adapted to be located over theopening in the flue or chimney where it is to be used. The casing a heroshown is in the form of a rectangular box but any appropriate form maybe used. Preferably the walls forming the top, sides and bottom of thiseasing or frame are inclined inwardly. The forward edges of the oppositesides and of the bottom of the easing are provided with inturned flangesa, while the top of the frame terminates a slight distance short of thevertical plane coinciding with the inside face of these flanges so as toleave open or unobstructed shoulders c to receive and support the endsof the damper shaft. The Width of the space or slot between the frontedge of the top and the rear or inside face of the flanges u. should beof a width approximately equal to the thickness of the damper and theshaft to which it is attached, so that when the damper is in positionthis space is practically closed.

The damper itself comprises a sheet metal plate 7) rigidly secured to ashaft 0, the damper plate being of a width to overlap the inside edgesof the continuous flange a yet not wide enough to bind against the sideor bottom walls. The shaft 0 is formed with an upward extension or ,band0 and on this extension is adjustably supported a sheave or pulley (Z.This sheave or pulley is provided on its outer face with a pro jectingboss (1 which is bored vertically to receive the extension 1; of thedamper shaft. This boss is also provided with a set screw 11 so as topermit the adjustment of the sheave up and down said extension arm c.The sheave (Z is also provided with a radial slot shown at. d whichextends from the periphery somewhat beyond the center of the sheave sothat the sheave may be adjusted with the sides of the slot astride ofthe shaft with the center of the sheave concentric with the axis ofrotation of the shaft. Around the periphery of the sheave is formed thegroove (1 which receives a chain c or similar tlcxible support, the samebeing held in position on the sheave by means of a removable pin 4'..llaeh end of the weight-carrying chain c is provided with aweight-carrying rod 6 which is of the usual constructon employed inscales except that instead of being cylindrical for its whole length,the upper part of these r'ods are flattened as shown at 0 Thecounterbalaneing weights are formed with keyhole slots, the enlargedcentral portion of the slot being of a size to receive the round portionof the weight rod 6', while the narrower portion of the slot is ofsullicient width to pass over the thin or flat upper portion of the rod.By this construction, the weights when in operative position shown inFig. 2, are securely locked against any accidental displacement whichwould cause them to fall oif the weight rods.

By reason of the peculiar construction of the casing it is possible toremove or to i11- sert the damper without the slightest ditliculty,since all that is necessary is to lift it vertically. Moreover, withthis construction no nice fitting is required and the ditli culty of thesticking or binding of the damper due to the rusting of the parts, whichI have encountered in the construction shown in my earlier Patent No.656,959 dated August 28, 1900, is entirely overcome.

By the system of counterbalance weights, I obtain a wide range ofregulation and where the draft is unusually strong it is possible byadjusting the sheave to a higher point above the damper shaft to get alonger leverage and more powerful action of the weights. According tothe arrangement of counterbalance weights therefor, the raising andlowering of the adjustable sheave will result in lessening or increasingof the current of air admitted through the damper passage into the flueor offtake.

In practice the action is as follows 2- When the damper b is closed,which is its normal position due to the action of regulat-ing weights,the draft in the flue with which the damper communicates is unaffected.If, however, the force of the draft becomes too great, the effect is toproduce a partial vacuum on the inside of the damper so that thepressure inside is less than the action of the outside atmosphericpressure, hence the damper opens to admit the outside air, which resultsin checking the draft. By reason of the adjustment of the sheave awayfrom the center, the action of the controlling weight becomes greaterand greater, the wider the damper opens, so as to afford. a continuallyincreasing resistance to the opening of the damper, and an increasingtendency to return the damper to closed po sition. This regulation makesit possible to prevent the checking of the draft too suddenly, while theinitial opening of the damper is regulated and controlled by theadjustment of the counterbalance weights.

What I claim is:

1. A draft-regulating damper embracing in its construction a hollowframe or casing open at front and rear, a damper-supporting shaft, adamper plate secured thereto and suspended therefrom to close the frontopening, a pulley or sheave secured to said shaft adjustable fromconcentric to eccentric position with relation to said shaft, andregulating weights suspended by means passing over and secured to saidpulley, substantially as described.

2. In a draft-regulating damper the combination with the casing orframe, of the damper, its supporting shaft provided with an upturnedarm, a sheave adjustable up and down said arm, a chain passed over saidsheave and secured thereto, the ends of said chain being provided withweightcarrying means, substantially as described.

3. In a draft-regulating damper the combination of acasing, the swingingdamper, the shaft to which said damper is secured, said shaft beingprovided with an upturned arm, a sheave adj ustably secured to said armand provided with a radial slot adapted to receive said shaft to permitthe sheave to be centered on the shaft, a weight-carrying chain securedto said sheave, substantially as described.

at. T he combination of the casing or frame, the swinging damper and itssupporting shaft, a sheave secured to said damper, a chain secured tosaid sheave, a weight rod secured to each end of said chain, said weightrod being of cylindrical form and flattened at its upper end, a seriesof weights provided with keyhole slots for permitting their beingattached to said rod and automatically locked thereto, substantially asdescribed.

In witness whereof, I have subscribed the above specification.

IVALTER 1B. FO WLER.

In the presence of- G. A. RooKwnLL, Gno. N. GODDARD.

